1. Technical Field
The present invention relates in general to ventilating enclosed or partially enclosed spaces. More particularly, the present invention relates to portable ventilation equipment and methods for deploying and using the same. Still more particularly, the present invention relates to a ventilation system including an integrated ventilation discharge adapter advantageously deployed in concert with a water-powered exhaust blower.
2. Description of the Related Art
The need for fast and efficient removal of atmospheric hazards within confined or partially confined spaces arises in many situations. Ventilation systems are required in such situations in which smoke, contaminated air or toxic gasses are generated or leak into interior compartmentalized spaces such as those found on ships. Removal of smoke or hazardous gases from remote spaces such as encountered during or following a fire in a ship may require that such gases or the fresh air be transported through long ducts at high gas flow or air flow velocities. In most emergency situations it is desirable that the ventilation equipment utilized in removing airborne hazards be sufficiently light and compact to be transported and installed by a minimum number of individuals.
For many shipboard environments such as machinery spaces, the fans or blowers utilized to provide the required suction in such ventilation systems are preferably capable of operating in volatile environments without causing an explosion. In addition, it is critical in many emergency ventilation scenarios that such blowers remain operable in the event that local electrical power source is lost or inaccessible. Water-driven turbine blowers, sometimes referred to as water-powered ram fans, address the foregoing emergency ventilation needs by employing a hydrodynamic turbine mechanism to generate the requisite fan suction. The use of water-driven blowers is well known in the art. For example, U.S. Pat. No. 5,125,797 describes a water turbine driven fan system that includes an air expansion nozzle in combination with a high velocity, high pressure rise fan that provides a means for generating substantial increases in air flow rate.
Large ships, such as Navy vessels and cargo ships, have interiors that are divided by bulkheads into a large number of compartments in order to more readily contain water and fire in case of a fire and/or flooding emergency. In the event of a fire, a standard technique is to temporarily seal off the compartment opening and exhaust the smoke through a portable flexible duct assembly, sometimes referred to as an “elephant trunk.” A water-powered turbine blower generates suction, and the exhaust end of the flexible duct is extended out through the deck hatches and/or watertight doors such that the smoke is exhausted from the affected interior space into the atmosphere. The water used to operate the blower is discharged either directly overboard from hoses running through open deck hatches or into the ship's gravity drainage system (e.g. deck drains or deep sink) from which it may be pumped by firemain pumps through overboard discharge fittings in the ship's hull.
A problem associated with using water turbine fans in emergency shipboard circumstances arises from the need to maintain airtight and watertight integrity and the limited water retention capacity of the ship. When a water-driven ram fan is used to ventilate a shipboard compartment, the air duct and water discharge hoses must be extended out through hatchways such that the smoke is exhausted into the atmosphere. Opening watertight doors or hatches from the affected space exposes many other ship compartments and walkways to the harmful atmospheric conditions sought to be expelled. The need to open sometimes multiple hatches during emergency ventilation procedures is further necessitated by the ship's limited water retention capacity requiring extending water hoses through passageways such that the water used to drive the ram fan may be discharged overboard. The dangers associated with a non-sealed ventilation expulsion may be particularly acute when the vented air contains chemical, biological, or radioactive components.
Systems for ventilating contaminated atmospheric conditions are described in U.S. Pat. No. 4,986,364 issued to Clark, and U.S. Pat. No. 2,436,038 issued to Farrell. Clark describes a dual purpose fire fighting and ventilation apparatus comprising a rigid conduit having a water inlet and a fogging nozzle outlet that is used to direct a spray aspiration action to draw smoke and air outwardly from an affected compartment through a non-sealed opening such as a doorway or opening. Farrell discloses a smoke ejector apparatus, which similar to Clark, includes a spray nozzle for directing a water spray to mix with smoke laden gases and direct the gases in an outward direction through an open doorway or window. While providing a means to expel and scrub smoke laden air from an opening in an affected space including the use of spray jet nozzles to facilitate the air outflow, neither Farrell nor Clark address the aforementioned problems related to shipboard ingress and egress containment issues particularly those related to maintaining sealed integrity of the forced-air gas exhaust outflow at the high volumetric flow rates produced by water-driven blowers.
It can therefore be appreciated that a need exists for a safer and more efficient system for removing hazardous atmospheric conditions occurring in the interior spaces and compartments of a ship. The present invention addresses such a need.